A receiving antenna should be aligned with respect to the source of transmitted signals for optimal signal reception. In the case of a satellite television system, this means accurately pointing the axis of a dish-like antenna so that an optimal picture is displayed on the screen of an associated television receiver.
The antenna alignment may be facilitated by the use of a signal strength meter or other measurement instrument which is temporarily connected to the receiving antenna for measuring the amplitude of the received signal directly at the antenna. However, a consumer will not ordinarily have access to a signal strength meter and will therefore have to rely on a trial and error method by which the antenna is adjusted and thereafter the image which is produced on the screen of an associated television receiver is observed. This requires either walking back and forth between the antenna and the television receiver or having someone else observe the image on the screen of the television receiver.
U.S. Pat. No. 4,893,288, entitled "Audible Antenna Alignment Apparatus" issued to Gerhard Maier and Veit Ambruster on Jan. 9, 1990, discloses an apparatus for adjusting a satellite receiving antenna which produces an audible response in response to the amplitude of an intermediate frequency (IF) signal derived from the received signal. The frequency of the audible response is inversely related to the amplitude of the IF signal. The frequency of the audible response is high when the antenna is misaligned and the amplitude of the IF signal is low. The frequency of the audible response decreases as the antenna is brought into alignment and the amplitude of the IF signal increases. Such audible antenna alignment apparatus enables a consumer to align a satellite receiving antenna without the need for expensive equipment or the technical expertise to use it. Moreover, it allows a user to align the antenna without help. However, it may be difficult for a user to accurately position the antenna by judging the continuously variable frequency of the audible signal.